This paper analyzes the problem that long dominated Claudio Napoleoni’s thinking on the “Sraffa problem”, or the judgement on the “real theoretical scope” of the propositions contained in the Sraffa’s 1960 book, Production of Commodities by Means of Commodities. Thus, the paper enquires into Napoleoni’s view of the book’s epistemological significance, from his review in the Giornale degli economisti (1961) and Il pensiero economico del 900 (1961), to Valore (1976), up to Il Discorso sull’economia politica (1985) and other papers representing the main passages in Napoleoni’s thinking. According to Napoleoni, Sraffa’s book is the final outcome of the modern critical reflections on economic science that started with Vilfredo Pareto and Gustav Cassel at the beginning of the twentieth century. But, Napoleoni maintains, abandoning the category of value, or reducing it to the category of price, means renouncing a principle of judgement, which implies that economic theory loses relevance.